Lightspeed Attenuator a new passive preamp


I've looked at that one Merlin. Although I can't make sense out of how to implement it. If the pot on the lightspeed just supplies 5v, then all the "stuff" on that board would be for naut. However, there is a really good chance that I am missing something.

What I "think" I need is just a pot with a motor on the back and some form of remote control.
 
I've looked at that one Merlin. Although I can't make sense out of how to implement it. If the pot on the lightspeed just supplies 5v, then all the "stuff" on that board would be for naut. .

A few of my customers who are lounge lizards have used this RC volume control that I put them onto, you do need all that's there, as it is the power and receiver circuit for the remote the power and driver for the motorized pot, and the relay input switching circuit. The only thing you need to do is to do a bit of surgery to the input/output tracks of the volume control to make it the same as the Lightspeed Attenuator (attached). Also it is not from what I've been told a genuine Alps pot and it is very course in it's action and they seem to think the remote will not last too many years.

Cheers George
 

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The carbon film tracks are etched/lazered on a single blank.
The common between input and output is indeed common for both channels.
I don't have the skills necessary to cut the track at common and reattach the lead out wiper, to create two separate tracks.

If you have some other pot that can be hung on the end of the motor then it may be possible to convert this MV02 kit into the driver pot for a Lightspeed.

I do have the pot and gearing mechanism open to take a pic or ten, if you think that modifying the pot is possible.

The operating software in the controller is a bit odd.
 
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I've looked at that one Merlin. Although I can't make sense out of how to implement it. If the pot on the lightspeed just supplies 5v, then all the "stuff" on that board would be for naut. However, there is a really good chance that I am missing something.

What I "think" I need is just a pot with a motor on the back and some form of remote control.

If you are into keeping it simple, you can buy a motorized dual gang Alps pot from Mouser and other sources, (under $20) and then wire it to a remote control box - i.e. wired remote control. Bent Audio also sells raw remote control kits, probably higher quality/better support, (but for more $) than Chinese stuff on Ebay.
http://www.bentaudio.com/index2.html
http://www.bentaudio.com/DLFILES/REM-ALPS-R1.pdf

Looking at the manual, this one also needs the traces cut into/out of the pot cut and then wired manually. Also note it is 50K, not 100K.
 
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Suitable volumn pots for LSA

I would like to use two mono pots instead of a dual for better control of channel balance. Can someone recommend a suitable device from Mouser or Digikey. Digikey has KA1041S28-ND, would this be ok ?

Also my current active preamp uses two 10k audio taper volumn pots, can these be used with the LSA ?
 
I would like to use two mono pots instead of a dual for better control of channel balance. Can someone recommend a suitable device from Mouser or Digikey. Digikey has KA1041S28-ND, would this be ok ?

Also my current active preamp uses two 10k audio taper volumn pots, can these be used with the LSA ?

these Alpha 100K dual log pots are an incredible buy for 2.73 each
see figure E part 313-2420F-100K

http://www.mouser.com/catalog/catalogUSD/645/824.pdf
http://www.mouser.com/catalog/specsheets/TW-700160.pdf

I have one here, tests smooth and works very well, with great resolution.

Then there are the Alps here
http://www.mouser.com/Catalog/catalogusd/645/825.pdf

The 3 in the upper right, dual, 100K, for $11.71

The differences between them are shaft length, and slotted, or D flat.
The 15A taper is typical audio log, plot shown here

http://www.alps.com/products/WebObjects/catalog.woa/E/PDF/Potentiometer/MetalShaft/RK271/RK271.PDF

I'd get this one, the D flat shaft
RK27112A0A16 ALPS Potentiometers
 
Many Thanks.

The single 688-RK2711120026 looks great, I will order that one.

It was not a mistake that dual section pots were recommended above.

If you go dual mono with the Lightspeed design, you'll still need to buy quantity 2 dual section pots.

There is no way that 2 single section pots will work for the lightspeed implementation of the circuit.

One pot section drives the LEDs for the upper (series R) LEDs, the 2nd section of the dual pot drives the lower LEDs (shunt R). In the standard configuration, each pot section drives both L and R LEDs.

So buy 2 100K dual gang pots for dual mono.

FYI, the power ratings on the pots above (from datasheets) - Alps pots are rated 50mW, the Alpha 250mW.
 
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